Hello and welcome.
Without further information, my guess would be that the font used in the file isn't loaded in your machine, and it wasn't properly embedded in the file.
I don't think that it has anything to do with the file. I've tried to open a number of different files, from a number of different senders and the same things happen. Sometimes when I open the file directly from my email it comes out all jumbled, but when I save to my desktop it opens (mostly) normal. Has anyone ever seen this? Is it possible to just uninstall and reinstall ADOBE on Macs?